Multifunctional self-decontaminating surface coating

ABSTRACT

A coating having an adhesive hydrophilic polymer and an amphiphilic additive. The amphiphilic additive has a hydrophilic chain, a biocidal functional group bonded to the hydrophilic chain, and a hydrophobic moiety bonded to the hydrophilic chain or to the biocidal functional group. A method of forming a biocidal surface by providing an article, and coating the article with the above coating. A compound having the formula: 
       Y—(O—CH 2 —CH 2 ) n —R—(CH 2 ) m —CH 3 .
 
     Y is CH 3  or H. R is 
     
       
         
         
             
             
         
       
     
     X is a halogen, and m and n are independently selected positive integers.

This application is a divisional application of U.S. patent applicationSer. No. 11/183,305, which claims the benefit of U.S. Provisional PatentApplication Nos. 60/622,715 filed on Oct. 28, 2004 and 60/656,549 filedon Feb. 18, 2005, all incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is generally related to the fields of biocides andbiocidal and/or sporicidal coatings.

2. Description of the Related Art

Decontamination and neutralization of surfaces from bacteria and sporesis a complex process that involves multiple technologies and variousapproaches, depending on the nature and extent of contamination. Thereare a variety of commercially available biocides and antiviral coatings;however, there are very few that claim to be effective as sporicides.Moreover, many decontaminating agents and solvents used to prepare themmust be mixed onsite and applied for effective use.

The ability to decontaminate chemically-resistant, coated paintedsurfaces inoculated with anthrax spores is extremely important. Theanthrax spore is the most persistent of all biowarfare agents. To killthem, the most potent biocides/sporicides must be employed. Irradiationis frequently necessary and often ineffective due to the robustness ofdormant or weaponized spores. Such spores may remain dormant fordecades, yet are easily converted into the harmful or lethal vegetativeform within minutes under ideal conditions.

Most conventional liquid sporicidal agents fall into three broadcategories: halide releasing compounds (e.g., hypochlorites andiodophores), reactive oxygen releasing agents (e.g., peroxides andperacetic acid), and aldehydes (e.g., formalin and glutaraldehyde)(Russell, Clin. Microbiology Rev. 1990, 3, 99. All referencedpublications and patent documents are incorporated herein by reference).Activity of all of these agents depend on destruction of fundamentalmetabolic processes and organic structures, thus making them extremelyhazardous to personnel in many cases (Cross et al., Appl. Environ.Microbiol. 2003 69, 2245). Furthermore, many of these agents rely on thegeneration of very reactive chemical species and are thereby inherentlyunstable. Most commercial sterilants require activation prior to use andsubsequently lose effectiveness within hours. The efficacy of someagents such as hypochlorites is rapidly attenuated by the presence oforganic matter. Aldehydes are effective sporicides only at relativelyhigh concentrations as liquids and require high relative humidity foreffectiveness as vapors. Decontamination frequently utilizes extremelytoxic gases such as ethylene oxide, chlorine dioxide, and methylenebromide (Whitney et al., Emerging Infectious Diseases 2003, 9, 623).Sporicidal efficacy of these gasses requires high relative humidity, andtheir use requires very careful attention to personnel safety. Anthraxspores pose a particularly difficult problem with respect to monitoringthe success of the decontamination efforts. Previous literature reportsthat a variety of other functional groups have been effectively used asbiocides; however, none cite the utility in surface overcoatings (Parket al., Biomaterials 1998, 19, 851).

Utility of germinants in solution have also been previously reported toaid in the conversion of spores into the vegetative cellular form;however, no mention of using this in decontamination was made (Cross etal.).

Bacteriocides have received much attention by way of industrialproducts, patent literature, as well as, peer-reviewed literature(Block, S. S. (ed.), 1991, Disinfection, sterilization and preservation,4^(th) edition. Lea & Febiger, Philadelphia, Pa.; Russell, A., D., W. B.Hugo and G. A. J. Ayliffe, 1992, Principles and practice ofdisinfection, preservation and sterilization. Blackwell ScientificPublications, London, U.K.). There have been many reports and patentsdealing with the benefits of having surfaces capable of killing bacteriaon contact (Ackart et al., J. Biomed. Mater. 1975, 9, 55-68; Endo etal., Appl. Environ. Microbiol. 1987, 53, 2050-2055; Gottenbos et al.,Biomaterials 2002, 23, 1417-1423; Ottersbach et al., U.S. Pat. No.5,967,714; Speir et al., J. Colloid Interface Sci. 1982, 89, 68-76;Tiller et al., Biotechnol. Bioeng. 2002, 79, 465-471; Tiller et al.,Proc. Natl. Acad. Sci. 2002 98, 5981-5985; Bauth et al., U.S. Pat. No.6,656,919). Despite the numerous reports, very few successful attemptsto kill spores, more importantly the anthrax spore (Bacillus anthracis),have been made. A unique spray approach is reported; however, itrequires treatment of a contaminated surface rather than serving as apreexisting coating (Bauth et al.). A common spore characteristic is theimpervious outer coat. These outer coatings are very resistant to cold,heat, drought, harsh chemicals, mild radiation, many sporicides, and UVradiation (Mock et al., Annu. Rev. Microbiol. 2001, 55, 647-671).

The cell wall of a typical 1-2 μm vegetative bacterium is very complex,with multiple layers outside the cytoplasmic membrane. The structure ofthe cell wall consists of an outer glycocalyx capsule layer atop of anS-layer, peptidoglycan layer, and finally a plasmic membrane protectingthe nucleus. In order to be effective, any biocide must be able topenetrate through this 40 nm outer wall consisting of layers such asglycocalyx, S-layer, peptidoglycan lipoteichoic acid layers to reach thevital parts in order to have an effect. Bactericidal functional groupsare well known and are documented to target the cell membrane. Suchproducts are currently commercially available as antiseptics,disinfectants, preservatives, sanitizers, water treatments, and swimmingpool treatments. It has been reported that the bactericide mechanismstarts with the adsorption onto a bacterial cell carboxylate surfacefollowed by diffusion through the outer layers of the cell. The bondingto the cytoplasmic membrane and disruption of this membrane to result inthe release of K⁺ ions through leakage occurs, which results indegradation of the cell structure and release of cell contents, thusresulting in the death of the cell.

Quaternary ammonium, pyridinium, and phenolic compounds are known topossess biocidal activity and have been used in a variety ofapplications and numerous commercially available products. Thesecompounds have not only found utility as biocides but also as phasetransfer catalysts and mobility systems designed to aid in the drugdelivery processes. They have also been reported to possess antisepticproperties.

SUMMARY OF THE INVENTION

The invention comprises a coating, comprising an adhesive hydrophilicpolymer and an amphiphilic additive. The amphiphilic additive comprisesa hydrophilic chain, a biocidal functional group bonded to thehydrophilic chain, and a hydrophobic moiety bonded to the hydrophilicchain or to the biocidal functional group.

The invention further comprises a method of forming a biocidal surfacecomprising providing an article, and coating the article with the abovecoating.

The invention further comprises a compound comprising the formula:

Y—(O—CH₂—CH₂)_(n)—R—(CH₂)_(m)—CH₃.

Y is CH₃ or H. R is selected from the group consisting of:

X is a halogen, and m and n are independently selected positiveintegers.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

In the following description, for purposes of explanation and notlimitation, specific details are set forth in order to provide athorough understanding of the present invention. However, it will beapparent to one skilled in the art that the present invention may bepracticed in other embodiments that depart from these specific details.In other instances, detailed descriptions of well-known methods anddevices are omitted so as to not obscure the description of the presentinvention with unnecessary detail.

The coating may be a multifunctional surface modifier. The coatings mayhave persistent bactericidal/bio-inhibitory activity coupled with abiocidal self-concentrating capability at polymer coating surfaces. Theapproach utilizes a hydrophobic/hydrophilic balance, such that thebactericidal functional group may self-orient toward the surface/airinterface while retaining enough hydrophilic character to be compatiblewith the hydrophilic resin system and promote moisture retention. Theapproach makes use of a hierarchical four-component molecular systemincorporated as an additive into selected polyurethane resin systems.The biocidal functional group is responsible for death of the cell. Thehydrophobic moiety is responsible for orientation of the biocidefunctionality toward the surface of the over-coating. The hydrophilicchain functions to attract and retain moisture and for compatibilitywith the hydrophilic resin system. This may function in conjunction withthe selected resin system to provide the needed moisture to germinatespores into the vegetative state. Finally, the adhesive polymer servesas a hydrophilic matrix for the dispersed or covalently bondedadditives, a moisture reservoir and a conformal coating.

Although the spore form of Bacillus anthracis is extremely resistant tochemical disinfectants, the vegetative form of this bacterium issusceptible to conventional anti-bacterial compounds. The germination ofbacterial spores is a studied phenomenon, and compounds(nutrients/germinants) that induce spore germination in liquid mediumhave been identified. These germinants are active at low concentrations,act very quickly, and may be very species specific. Bacillus anthracisgerminants can be incorporated into the described coating systems, insuch a way that adherent spores will be induced to germinate. Once thespores are converted into vegetative cells, they may be subsequentlykilled by the biocides present in the coating. This approach caneliminate the need to introduce highly toxic, short-lived, corrosivesporicides into the coating. Avoiding dependence on highly reactiveshort-lived chemicals can also dramatically increase the effective lifeof the top coating.

In one embodiment, the invention is a coating comprising an adhesivepolymer and an amphiphilic additive as stated above. The coating may beapplied to the surface of an article to give the surface biocidalproperties.

The adhesive polymer facilitates binding to a substrate. Suitableadhesive hydrophilic polymers include, but are not limited to,polyurethanes, polyurethane hydrogels such as HYDROTHANE™ (CardioTechInternational, Inc), epoxies, polyesters, and polyacrylates. Noparticular minimum level of adhesiveness or hydrophilicity is required.The polymer need only adhere to a surface to be coated to a degreesuitable for the manner in which the coated article is to be used. Thepolymer need only be hydrophilic enough to serve as a moisture reservoirfor spore germination and to concentrate the amphiliphilic biocidaladditive at the surface. The term “adhesive hydrophilic polymer”includes single polymers and combinations and mixtures of two or morepolymers.

The hydrophilic chain of the amphiphilic additive is generally presentin order to maintain the additive as part of the coating, through itsattraction to the polymer, though it is not limited to such use. Thehydrophilic chain may incorporate into the polymer by a variety ofmethods such as hydrogen bonding, covalent bonding, ionic coordination,or chain entanglement. The hydrophilic chain may also function as anattractive area for moisture absorption and as a promoter ofgermination. The hydrophilic chain may form a layer between the adhesivepolymer and the biocidal group/hydrophobic moiety. The hydrophilic layermay include of several factors, such as physical or chemical bonding toan adhesive polymeric backbone, providing a source of moisture topromote the conversion from spore to vegetative bacterial cell,providing germinants to promote the conversion from spore to vegetativestate, providing nutrients to promote the conversion from spore tovegetative state, attachment to a biocide functionality that willself-orientate towards the surface, and attachment to a biocidefunctionality that has the ability to kill the vegetative cell.

Suitable hydrophilic chains include, but are not limited to, oxyethyleneoligomers and oxypropylene oligomers, including oligomers having 1, 2,3, 4, 5, 6, 7, or 8 repeat units and/or terminating in methyl orhydroxyl. Oxyethylene is generally more hydrophilic than oxypropyleneand may have a greater attraction to the polymer. The additive maycontain a single hydrophilic chain or multiple hydrophilic chains thatare the same or different, and the coating may contain two or moreadditives containing the same or different chains.

The hydrophobic moiety is generally present, though it is not limited tosuch use, in order to orient the additive such that the biocidal groupis preferentially near or at the surface of the coating, thus allowingthe biocidal component to be at the surface of the coating and notburied within the polymeric layer. No particular minimum level ofhydrophobicity is required. Suitable hydrophobic moieties include, butare not limited to, alkyl groups, including linear alkyl groups having2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 carbonatoms. The additive may contain a single moiety or multiple moietiesthat are the same or different, and the coating may contain two or moreadditives containing the same or different moieties.

The biocidal functional group is generally present in order to kill orbe damaging to bacteria that come in contact with the coating, though itis not limited to such use. Suitable biocidal groups include, but arenot limited to, quaternary ammonium salts, pyridinium salts, andphenols. The additive may contain a single biocidal group or multiplebiocidal groups that are the same or different, and the coating maycontain two or more additives containing the same or different biocidalgroups. Suitable amounts of the amphiphilic additive or of the biocidalfunctional group include, but are not limited to, up to 5% or up to 1%by weight of the coating, such as 0.5% to 1%.

The amphiphilic additive may have the following structure:

Y—(O—CH₂—CH₂)_(n)—R—(CH₂)_(m)—CH₃.

Y is CH₃ or H. R is selected from the group consisting of:

X is a halogen, such as Cl, Br, or I; m is an integer from 1 to 17; andn is an integer from 1 to 8. In this class of compounds,Y—(O—CH₂—CH₂)_(n) is the hydrophilic chain, (CH₂)_(m)—CH₃ is thehydrophobic moiety, and R is the biocidal group. The three R groups are,respectively, a quaternary ammonium salt, a pyridinium salt, and aphenol. The coating may comprise more than one of these compounds havingmore than one value for m, n, or both m and n, such that the coating asa whole has a non-integer average value for m and/or n.

In another embodiment, the coating comprises a germinating agent inaddition to the amphiphilic additive. The germinant is generally presentin order to stimulate conversion of a bacterium from spore form tovegetative form, though it is not limited to such use. An example ofsuch a bacteria is Bacillus anthracis. The biocidal group may not haveany effect on a spore, but once the germinating group causes theconversion, the biocidal group may act on the bacteria. Suitablegerminating agents include, but are not limited to, L-alanine andL-methionine. More than one germinating agent may also be present in thecoating. Suitable amounts of the germinating agent include, but are notlimited to, up to 5% or up to 1% by weight of the coating.

The germinating coating may also comprise a nutrient. The nutrient isgenerally present to support development of the bacteria from the sporeto the vegetative state. Suitable nutrients include, but are not limitedto, Luria broth, and/or Yeast Extract and the compounds shown below.More than one nutrient may also be present in the coating. Suitableamounts of the nutrient include, but are not limited to, up to 5% or 1%by weight of the coating.

Features may include the ability for deposition as a polymeric thin filmcoating, controlled surface morphology/composition, promotion of sporegermination, and bactericidal action. It involves the complex chemicaland biological interactions acting across two dynamic interfaces orinter-phases between the bacteria/spore and the polymer coating. Theconcept for self-decontaminating surfaces is applicable to otherbioagents besides Bacillus anthracis spores, such as Yersinia pestis(plaque) and Francisella tularensis (tularemia), as well as otherpathogenic bacteria.

The coating or additive may be applied to a variety of surfaces tofunction as a self-decontaminator and function as a biocide, sporicide,and an antiviral agent. Several potential uses include children's toys,doorknobs, food preparation surfaces, air handling ducts, militaryequipment, military vehicles, public transportation surfaces, and otherareas that are easily contaminated or areas that are in high risk ofbiological terrorist attacks. The coating may facilitate decontaminationin enclosed or field areas.

Possible advantages may include eliminating the need for causticchemicals, caustic sporicides, radiation, or precise environments to rida surface of spores. This self-decontaminating coating or additive canallow for germination due to the presence of nutrients, germinants(including cogerminants), moisture, and biocidal functionality allincorporated at the surface of the coating and, thus, may be contactedby spores landing on the surface. The coating may be constantly activeand may require no activation or special control of atmosphericconditions.

Another embodiment is compounds having the structure shown above, wherem and n are independently selected positive integers. This embodimentincludes mixtures of more than one such compounds having differentvalues for m, n, or both m and n. Examples are shown below as well asexample synthetic schemes. Suitable values for m are 1 to 17 and for nare 1 to 8, both including all numbers in between. This embodiment alsoincludes mixtures of these compounds having more than one value for m,n, or both m and n.

Results indicate that the three classes of compounds have shown success.The biocidal functional groups and hydrophobic-hydrophilic substructuresmay each be varied independently. For each class of biocide, the minimumoxyethylene chain length that afforded the maximum effectiveness wasincorporated into the selected resin systems. Depending upon the resinsystem selected, the minimum length was desirable in an attempt not tomask the hydrophobic substituent on the biocide, which dictated biocidalorientation within the coating. One of the many possible functionalgroups most suitable for incorporation into the resin systems describedmakes use of the acrylate moiety. The ability to retain the option tofunctionalize the hydrophilic chain with an acrylate may requiremodification to the synthetic approach (i.e., esterification) of theinitial starting reagent within the reaction scheme.

The efficacy of these structures was evaluated in solution, prior toundertaking the additional synthetic steps that converted the moleculesinto the corresponding additive. These surfactant-like biocides havedemonstrated effectiveness in killing bacteria not only in solution, butalso in resin systems (i.e., urethanes, HYDROTHANE™). These systems wereemployed in screening diagnostics to obtain measures of water absorptionand antimicrobial activity, which in turn may aid in the selection ofthe reported biocides. The lysing of the bacterial cells may result inthe conversion of the halide salt into the corresponding hydroxide insome cases when pyridinium salts and/or ammonium salt species wereemployed.

A progression of results was demonstrated with Anthrax spores depositedon a 20% (w/w) hydrated HYDROTHANE™ resin system, which displayed nosign of conversion to the cellular form after weeks of incubation. Thisconfirms that moisture alone on a surface or in the base resin systemmay not be sufficient to germinate Anthrax spores. When Anthrax sporeswere placed on the identical hydrated resin system, which included notonly moisture but also a mixture of germinants, the spores becamevegetative within hours. When the coating formulation included a biocide(i.e., quaternary ammonium biocide), very few spores remained and nogrowing bacteria remained on the surface. As a result of these initialevaluations, it was concluded that the spores germinated with the aid ofboth the moisture and germinant mixture within the polyurethane resinsystem. Subsequently, the bactericidal action of the ammonium salteffectively inactivated the resulting Anthrax cells, rendering aharmless surface. The proposed biocides are of a non-toxic character incontrast to many current heavy metal biocides.

Germinant/nutrient selection promoting vegetation of dormant anthraxspores is a very complex procedure because Bacillus anthracis does notrely on a single signal to promote spore germination. Receptor proteinson the spore's membrane bind to ring-shaped or aromatic structures oncertain amino acids (building blocks of proteins) and purineribonucleosides (building blocks of DNA and RNA). Small molecules orgerminants have been reported to trigger spore germination for variousbacterial spores (Clements et al., J. Bacteriol. 1998, 180, 6729; McCannet al., Lett. Appl. Microbiol. 1996, 23, 290; Rossignol et al., J.Bacteriol. 1979, 138, 431; Rossignol et al., Biochem. Biophys. Res,Commun. 1979, 89, 547; Vary et al., J. Bacteriol. 1968, 95, 1327; Mocket al., Annu. Rev. Microbiol. 2001, 55, 647; Hills, Biochem. J. 1949,445, 363). Some reports specifically address Anthrax spores and citeL-alanine, purine, tryptophan, and tyrosine for Bacillus anthracisendospore germination, however; D-alanine inhibited germination (Titballet al., J. Appl. Bacteriol. 1987, 62, 269). Also, commerciallyformulated complex broths are used to culture various bacteria, and acombination of moisture and germinant are desirable for sporegermination. The germination activity may be attributed to receptorproteins on the spore's membrane binding to heterocyclic aromaticstructures and selected amino acids, resulting in conversion to thevegetative cellular form.

Spores have a redundant germination mechanism, which ensures they do notgerminate until conditions are ideal. Small molecules or germinants havebeen found to trigger this process. Germinants that trigger the processinclude L-alanine in Bacillus subtilis, L-proline in Bacillusmegaterium, and inosine in Bacillus cereus have been reported (Clementset al; McCann et al.; Rossignol et al., J. Bacteriol.; Rossigno et al.,Biochem. Biophys. Res. Commun; Vary et al.). The germination of Bacillusanthracis endospores has been studied sporadically over the past sixtyyears. In 1949, Hills showed that germination was influenced byL-alanine, tyrosine, and adenosine (Hills Biochem. J. 1949, 445,363-370). In 1987, Titball and Manchee showed L-alanine initiatedBacillus anthracis endospore germination, while D-alanine inhibitedgermination (Titball et al.).

A series of antimicrobial testing and results indicate success. A seriesof Gram-positive and Gram-negative bacteria were tested by four testmethods (live/dead bacterial viability staining, disk diffusion test,tube dilution method with neutralization agent to quench residualbiocide activity and coated glass slide). The following Gram-positivebacteria were used in the biocide tests: Bacillus anthracis Sternestrain, Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureusand Staphylococcus epidermidis. The following Gram-negative bacteriawere used in the biocide tests: Escherichia coli, Klebsiella pneumoniae,Pseudomonas aeruginosa, Salmonella typhimurium, Enterobacter cloacae,Proteus vulgaris, and Serratia marcescens. The prescreening of a seriesof model biocide compounds was very successful in killing vegetativebacterial cells for all functionalities of interest.

The approach of the present invention is designed to accelerate sporegermination by the addition of known cogerminants for Bacillus anthracissuch as L-alanine+L-amino acids (trp, tyr, pro, his); inosine witharomatic and non-aromatic L-amino acids (trp, tyr, phe, his, pro, phe,ser, val, ser) (Ireland et al., Medicine at Michigan 2002 4:12; Irelandet al., J. Bacteriol. 2002 184:1296-1303). In the present invention, thefollowing cogerminants may be added to the coating system: polyL-alanine, poly-L-tryptophan (various molecular weights),poly-L-tyrosine (various molecular weights), poly-L-amino acid peptides,inosine, ATP, etc. Addition of pigments, fillers, polyester, amides,poly L-alanine, Yeast Extract, Luria Broth, etc. can act as nutrients inthe presence of moisture.

Identification of key components/compounds that are strong promoters ofspore germination is necessary. Results employing commercial mixtures ofgerminants (e.g., Luria Broth (LB)), a mixture consisting of yeastextract, tryptone and sodium chloride has shown success, when employedin 0.1-20% (w/w) concentrations within the hydrophilic resin system.Yeast extract with various L-amino acids (i.e., L-alanine, L-methionine,etc.) has shown success as germinants for Bacillus anthracis spores.

Screening may be conducted employing a variety of amino acids,heterocyclics, and components of commercial growth media. The rapidscreening and down selection from an extensive list of the germinantsmay allow for rapid optimization. The germinants may be ranked anddown-selected according to time dependence for germination. The moreeffective germinant candidates have demonstrated the minimum effectiveconcentration required for the desired response within the resin system.After selection in the test resin system, the germinants were thenoptimized for the final selected resin coating system.

Having described the invention, the following examples are given toillustrate specific applications of the invention. These specificexamples are not intended to limit the scope of the invention describedin this application.

Example 1

General procedure for preparation of methoxy terminated quaternaryammonium salts—In a 20 mL round bottomed flask equipped with refluxcondenser and a positive flow of nitrogen were placed a tertiary amine(6.36 mmol), a bromo-ethyleneglycol monomethyl ether (6.36 mmol), andabsolute ethanol (17.49 mmol). The solution was heated in an 83° C. oilbath for 24 hr. The resulting solution was allowed to slowly cool to RTand concentrated under reduced pressure. The resulting thick yellow oilwas titrated with petroleum ether (2×3 mL), and placed under vacuum toremove trace solvent. The resulting product was dissolved in 2 mL ofEtOH with vigorous stirring and then cooled to −30° C. to result incrystallization of the desired product. A second crop of equal puritymay be recovered by recrystallization of the mother liquor.

Example 2

Characterization of methoxy terminated quaternary ammoniumsalts—Hexyl-[2-(2-methoxy-ethoxy)-ethyl]-dimethyl-ammonium bromide:FTIR: 3013, 2954, 2921, 2878, 1463, 1253, 1194 cm⁻¹. ¹H NMR (CDCl₃):3.99-3.92 (dd, 4H), 3.72-3.58 (m, 4H), 3.54-3.51 (m, 2H), 3.42 (s, 6H),3.36 (s, 3H), 1.78-1.74 (m, 2H), 1.34-1.31 (m, 6H), 0.90 (t, J=7, 3H) δ.¹³C NMR (CDCl₃): 71.4, 70.3, 65.7, 64.9, 62.8, 58.8, 58.0, 51.8, 31.1,25.7, 22.7, 22.3, 13.7 δ. Anal. Calcd for C₁₃H₃₀BrNO₂: C, 50.00; H,9.68; N, 4.49. Found: C, 49.87; H, 9.71; N, 4.49.

Hexyl-(2-methoxy-ethyl)-dimethyl-ammonium bromide—FTIR: 3005, 2949,2922, 2854, 2811, 1467, 1408, 1380, 1265, 1118, 1078, 1031, 729 cm⁻¹. ¹HNMR (CDCl₃): 3.95-3.87 (dd, 4H), 3.61 (t, J=8, 2H), 3.43 (s, 6H), 3.40(s, 3H), 1.79-1.61 (m, 2H), 1.37-1.31 (m, 6H), 0.89 δ (t, J=7, 3H). ¹³CNMR (CDCl₃): 65.9, 65.2, 62.5, 58.6, 51.3, 30.6, 25.3, 22.2, 21.8, 17.9,13.4 δ. Anal. Calcd for C₁₁H₂₆BrNO: C, 49.25; H, 9.77; N, 5.22. Found:C, 49.21; H, 9.75; N, 5.25.

(2-Methoxy-ethyl)-dimethyl-octyl-ammonium bromide—FTIR: 3005, 2949,2921, 2850, 2810, 1467, 1122, 1031, 722 cm⁻¹. ¹H NMR (CDCl₃): 3.94 (d,J=5, 2H), 3.87 (d, J=5, 2H), 3.87-3.62 (m, 2H), 3.43 (s, 6H), 3.39 (s,3H), 1.34-1.24 (m, 10H), 1.78-1.72 (m, 2H), 0.88 (t, J=7, 3H) δ. ¹³C NMR(CDCl₃): δ6.4, 65.9, 63.0, 59.1, 51.8, 31.6, 29.0, 28.9, 26.2, 22.8,22.5, 14.0 δ. Anal. Calcd for C₁₃H₃₀BrNO: C, 52.70; H, 10.21; N, 4.73.Found: C, 52.32; H, 10.14; N, 4.77.

[2-(2-Methoxy-ethoxy)-ethyl]-dimethyl-octyl-ammonium bromide—FTIR: 3009,2954, 2922, 2851, 2815, 1471, 1360, 1134, 1099, 1071, 1015, 976, 841cm⁻¹. ¹H NMR (CDCl₃): 3.95-3.91 (m, 4H), 3.72-3.52 (m, 6H), 3.40 (s,3H), 3.35 (s, 6H), 1.78-1.72 (m, 2H), 1.34-1.21 (m, 10H), 0.90 (t, ∂=7,3H) δ. ¹³C NMR (CDCl₃): 71.4, 70.3, 65.8, 64.9, 62.8, 58.8, 58.0, 51.8,31.5, 28.9, 26.1, 22.8, 22.4, 18.3, 13.9 δ. Anal. Calcd for C₁₅H₃₄BrNO₂:C, 52.94; H, 10.07; N, 4.12. Found: C, 52.71; H, 10.27; N, 4.05.

Hexyl-(2-(2-(2-methoxy-ethoxy)-ethoxy)-ethyl)dimethylammonium bromide:FTIR: 3005, 2954, 2922, 2858, 1633, 1467, 1352, 1277, 1245, 1201, 1110,964 cm⁻¹. ¹H NMR (CDCl₃): 4.08-3.94 (m, 4H), 3.82-3.47 (m, 8H), 3.43 (s,6H), 3.37 (s, 3H), 1.77 (t, J=5, 2H), 1.35-1.21 (m, 8H), 0.89 δ (t, J=6,3H). ¹³C NMR (CDCl₃): 71.7, 71.0. 70.4, 70.2, 69.9, 65.7, 64.8, 58.8,51.7, 30.7, 25.8, 22.7, 18.3, 13.8 δ. Anal. Calcd for C₁₅H₃₄BrNO₃: C,50.56; H, 9.62; N, 3.93. Found: C, 50.75; H, 9.91; N, 3.65.

Hexyl-(2-(2-(2-(2-methoxy-ethoxy)-ethoxy)-ethoxy)-ethyl)dimethylammoniumbromide: FTIR: 3005, 2950, 2926, 2870, 1467, 1348, 1249, 1118, 964 cm⁻¹.¹H NMR (CDCl₃): 4.06-3.92 (m, 6H), 3.73-3.54 (m, 8H), 3.63 (s, 6H),3.47-3.37 (m, 2H), 3.37 (s, 3H), 1.76 (t, J=6, 2H), 1.38-1.30 (m, 8H),0.90 δ (t, J=6, 3H). ¹³C NMR (CDCl₃): 71.8, 70.5, 70.4, 70.3, 70.2,70.1, 65.9, 65.0, 63.0, 58.9, 51.8, 31.2, 25.8, 22.8, 22.7, 22.3, 13.8δ. Anal. Calcd for C₁₇H₃₈BrNO₄: C, 51.00; H, 9.57; N, 3.50. Found: C,50.59; H, 9.52; N, 3.87.

(2-(2-(2-Methoxy-ethoxy)-ethoxy)-ethyl)dimethyloctylammonium bromide:FTIR: 3009, 2957, 2924, 2856, 1627, 1465, 1356, 1275, 1243, 1198, 1125,968 cm⁻¹. ¹H NMR (CDCl₃): 4.12-3.87 (m, 4H), 3.63-3.47 (m, 8H), 3.42 (s,6H), 3.29 (s, 3H), 1.76 (t, J=5, 2H), 1.26-1.01 (m, 12H), 0.88 δ (t,J=6, 3H). ¹³C NMR (CDCl₃): 71.7, 70.9, 70.4, 70.3, 70.1, 69.9, 66.0,58.9, 51.8, 31.5, 29.0, 28.95, 26.2, 22.8, 22.5, 13.9 δ. Anal. Calcd forC₁₇H₃₈BrNO₃: C, 53.12; H, 9.96; N, 3.64. Found: C, 52.89; H, 9.77; N,3.46.

(2-(2-(2-(2-Methoxy-ethoxy)-ethoxy)-ethoxy)-ethyl)dimethyloctylammoniumbromide: FTIR: 3005, 2926, 2854, 1467, 1344, 1292, 1253, 1118, 975, 928cm¹. ¹H NMR (CDCl₃): 4.06-3.93 (m, 6H), 3.82-3.68 (m, 8H), 3.63 (s, 6H),3.39-3.38 (m, 2H), 3.45 (s, 3H), 1.76 (t, J=6, 2H), 1.35-1.21 (m, 12H),0.88 (t, J=6, 3H) δ. ¹³C NMR (CDCl₃): 71.7, 71.0, 70.4, 70.3, 70.2,65.8, 64.9, 62.8, 58.2, 51.7, 31.5, 30.6, 29.0, 28.9, 26.1, 22.7, 22.7,18.3, 13.9 δ. Anal. Calcd for C₁₉H₄₂BrNO₄: C, 53.26; H, 9.88; N, 3.27.Found: C, 52.89; H, 9.65; N, 3.24.

Example 3

General procedure for preparation of hydroxyl terminated quaternaryammonium salts—In a 15 mL round bottomed flask equipped with condenser,magnetic stir bar, and positive flow of nitrogen were placed amine (6.36mmol), 2-(2-chloroethyl)ethanol (0.79 g, 6.36 mmol), and 0.80 g ofabsolute EtOH (17.49 mmol). The resulting solution was allowed to stirin a 90° C. oil bath for 24 hr, after which time the solution wasallowed to cool to RT. The solution was concentrated under reducedpressure and tritrated with petroleum ether (3×2 mL). The resultingviscous oil was dissolved in 5 mL of EtOH and passed through a 3 cm plugof Sephadex G-25 resin with an additional 50 mL EtOH wash. The solutionwas concentrated to afford the desired product.

Example 4

Preparation of [2-(2-hydroxy-ethoxy)-ethyl]-dimethyl-octyl-ammoniumchloride—Dimethyl-octyl-amine (1.00 g, 6.36 mmol) was condensed with2-(2-chloro-ethoxy)-ethanol (1.19 g, 9.54 mmol) in a 25 mL roundbottomed flask equipped with magnetic stir bar and allowed to heat in a120° C. oil bath for 6 hrs. The solution was slowly cooled to roomtemperature, which resulted in semisolid formation. The resultingproduct was placed on vacuum at 1 mmHg and heated at 60° C. for 4 hrs toremove unreacted amine and starting material.

Example 5

Alternative preparation of[2-(2-hydroxy-ethoxy)-ethyl]-dimethyl-octyl-ammonium chloride—Into a 15mL round-bottomed flask with positive flow of nitrogen were placedN,N-dimethyloctylamine (6.36 mmol), 3 mL THF, and2-(2-chloro-ethoxy)-ethanol (6.36 mmol). The resulting solution wasallowed to reflux for 12 hr. Upon cooling to room temperature, thesolution was concentrated under reduced pressure and dried under reducedpressure at 100° C. to rid the product mixture from subsequent residualstarting material.

Example 6

Characterization of hydroxyl terminated quaternary ammoniumsalts—Octyl-(2-(2-hydroxy-ethoxy)-ethyl)dimethylammonium chloride: FTIR:3279, 3009, 2954, 2921, 2858, 1467, 1364, 1126, 1071, 971, 892 cm⁻¹. ¹HNMR (CDCl₃): 4.05 (d, J=6, 2H), 3.86 (t, J=6, 2H), 3.80-3.73 (m, 2H),3.69-3.54 (m, 4H), 3.41 (s, 6H), 2.67 (bs, 1-OH), 1.34-1.27 (m, 12H),0.885 (t, J=6, 3H). ¹³C NMR (CDCl₃): 72.9, 72.3, 71.0, 64.8, 61.5, 61.1,51.8, 42.9, 31.6, 28.9, 26.2, 22.8, 22.5, 14.0 δ. Anal. Calcd forC₁₄H₃₂ClNO₂: C, 59.66; H, 11.44; N, 4.97. Found: C, 59.81; H, 11.52; N,4.59.

Hexyl-(2-(2-hydroxy-ethoxy)-ethyl)dimethylammonium chloride: FTIR: 3229,3016, 2955, 2928, 2861, 1467, 1359, 1123, 1069, 965 cm¹. ¹H NMR (CDCl₃):3.87 (d, J=5, 2H), 3.69 (t, J=5, 2H), 3.63-3.37 (m, 4H), 3.23 (s, 6H),2.65 (bs, 1OH), 1.65-1.50 (m, 2H), 1.27-1.11 (m, 8H), 0.72 δ (t, J=7,3H). ¹³C NMR (CDCl₃): 73.0, 66.0, 63.5, 61.2, 51.8, 31.2, 25.9, 22.8,22.4, 18.4, 13.8 δ. Anal. Calcd for C₁₂H₂₈ClNO₂: C, 56.79; H, 11.12; N,5.52. Found: C, 56.82; H, 11.05; N, 5.74.

Example 7

General procedure for preparation of phenols—In a 25 mL round bottomedflask equipped with magnetic stir bar, Dean-Stark trap and condenserwere placed 4-Hexyl-benzene-1,3-diol (0.59 g, 6.25 mmol), anethyleneoxide monomethylether (6.25 mmol), p-toluenesulfonic acid (0.01g, 0.008 mmol), and 20 mL of toluene. An additional 7 mL of toluene wasplaced in the Dean-Stark trap to prevent taking the pot volume too low.The solution was allowed to reflux vigorously for 24 hours in an oilbath. The resulting solution was allowed to cool to room temperature,concentrated using the rotary evaporator. The resulting oil was elutedthrough a silica gel column employing a Hexane/EtOAc (1:1) solventsystem. The desired product eluted in the first fraction.

Example 8 Preparation of2-Hexyl-4-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenol—Toa solution of toluene-4-sulfonic acid2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethyl ester (1.87 g, 5.15mmol) dissolved in 50 mL tetrahydrofuran in a 100 mL round bottomedflask equipped with nitrogen inlet, condenser, and a stir bar was addeddropwise 2-hexyl-benzene-1,4-diol (1.00 g, 5.15 mmol). The resultingsolution was heated in an 80° C. oil bath for 12 hours with rigorousstirring. After such time, it was allowed to slowly cool to roomtemperature and was concentrated utilizing a rotary evaporator. Theresulting product was washed with deionized water (3×5 mL) to rid themixture of any residual by-product and then placed on the vacuum linefor 4 hours. The desired product,2-hexyl-4-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenol,was afforded in a 61% yield (1.22 g, 3.16 mmol). Example 9

Characterization of phenols-2-Hexyl-5-(2-methoxy-ethoxy)-phenol: FTIR:3362, 2950, 2930, 2858, 1606, 1519, 1463, 1376, 1297, 1221, 1162, 1114,1055, 972 cm⁻¹. ¹H NMR (CDCl₃): 6.91 (d, J=9, 1H), 6.34 (d, J=2, 1H),5.76 (d, J=5, 2H), 3.54 (d, J=5, 2H), 3.37 (s, 3H), 2.48 (t, J=8, 2H),1.55-1.50 (m, 2H), 1.34-1.25 (m, 6H), 0.87 δ (t, J=7, 3H). ¹³C NMR(CDCl₃): 154.3, 154.2, 130.7, 121.3, 107.5, 102.9, 73.4, 61.5, 58.7,31.7, 29.2, 29.1, 22.6, 14.1 δ.

2-Hexyl-5-[2-(2-methoxy-ethoxy)-ethoxy]-phenol: FTIR: 3346, 2961, 2922,2858, 1622, 1519, 1459, 1376, 1301, 1225, 1166, 1118, 968 cm⁻¹. ¹H NMR(CDCl₃): 6.92 (d, J=9, 1H), 6.36 (d, J=2, 1H), 6.32 (d, J=6, 1H), 5.37(bs, 10H), 3.78 (t, J=6, 2H), 3.66 (t, J=5, 2H), 3.63-3.59 (m, 4H), 3.42(s, 3H), 2.50 (t, J=6, 2H), 1.55-1.51 δ (m, 2H). ¹³C NMR (CDCl₃): 154.6,154.4, 130.6, 120.9, 107.4, 102.8, 72.2, 71.9, 69.9, 61.8, 58.9, 31.7,30.0, 29.2, 29.1, 22.6, 14.1 δ.

2-Hexyl-5-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-phenol (3c): FTIR:3345, 2950, 2913, 2851, 1626, 1601, 1519, 1459, 1380, 1348, 1301, 1217,976 cm⁻¹. ¹H NMR (CDCl₃): 6.91 (d, J=9, 1H), 6.41 (d, J=2, 1H), 6.33 (d,J=6, 1H), 3.77-3.73 (m, 2H), 3.70-3.56 (m, 10H), 3.38 (s, 3H), 2.50 (t,J=6, 2H), 1.55-1.49 (m, 2H), 1.33-1.27 (m, 6H), 0.87 δ (t, J=6, 3H). ¹³CNMR (CDCl₃): 155.0, 154.7, 130.5, 120.7, 106.9, 102.6, 72.4, 71.7, 70.5,70.3, 70.2, 61.6, 58.9, 31.8, 30.0, 29.3, 29.2, 22.6, 14.1 δ.

2-Hexyl-5-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-phenol:FTIR: 3342, 2930, 2858, 1618, 1606, 1523, 1459, 1344, 1301, 1253, 1198,1094, 980 cm⁻¹. ¹H NMR (CDCl₃): 6.91 (d, J=9, 1H), 6.41 (d, J=2, 1H),6.33 (d, J=6, 1H), 3.75 (t, J=6, 2H), 3.68-3.55 (m, 14H), 3.37 (s, 3H),2.50 (t, J=9, 2H), 1.55-1.52 (m, 2H), 1.33-1.24 (m, 6H), 0.87 δ (t, J=6,3H). ¹³C NMR (CDCl₃): 155.0, 154.7, 130.5, 120.7, 106.9, 102.7, 72.4,71.8, 70.5 (overlapping peak), 70.4, 70.3, 70.1, 61.7, 58.8, 31.8, 30.1,29.3, 29.2, 22.6, 14.1 δ.

Example 10

Preparation of1-hexyl-4-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]ethoxy}-ethoxy)-pyridiniumbromide—Pyridin-4-ol (1.50 g, 15.77 mmol) and toluene-4-sulfonic acid2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethyl ester (5.62 g, 19.71mmol) were combined in a 50 mL round bottomed flask equipped withcondenser, magnetic stir bar, and a positive flow of nitrogen. Thesolution was heated in a 100° C. oil bath for 24 hrs. The solution wasthen cooled and placed on a vacuum line at 1 mmHg and heated at 80° C.for 6 hrs to removed residual starting materials. The by-product wasremoved via washing with deionized water (3×15 mL) to afford4-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-pyridine. Theproduct may be subsequently purified employing column chromatographytechniques at this point or may proceed directly to the addition of1-bromohexane (3.90 g, 23.66 mmol) in 25 mL tetrahydrofuran. Stirringthe resulting reaction mixture at 50° C. for 24 hrs resulted in thedesired product,1-hexyl-4-(2-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-pyridiniumbromide in a 38% yield (2.70 g, 5.99 mmol).

Example 11

Preparation of1-hexyl-4-{2-[2-(2-methoxy-ethoxy)-ethoxy]-ethoxy}-pyridiniumbromide—Into a 25 mL round bottomed flask with positive flow ofnitrogen, were placed 4-hydroxy pyridine (2.14 mmol), toluene-4-sulfonicacid 2-[2-(2-methoxy-ethoxy)-ethoxy]-ethyl ester (2.36 mmol), and 15 mLTHF. The resulting solution was allowed to reflux for 24 hr, slowlyallowed to cool to room temperature and then treated with 1-chlorohexane(2.36 mmol), prior to bringing the solution to reflux once again for 6hr. The reaction mixture was concentrated under reduced pressure andtitrated with hexanes.

Example 12

Antimicrobial testing—Live/dead bacterial viability staining wasemployed. This is a two-color fluorescence assay of bacterial viability,which provided results in minutes. This is a quantitatively method usedto distinguish live and dead bacteria in minutes even in a mixedpopulation of bacterial types. SYTO-9 green fluorescent nucleic acidstain bacteria with intact membranes stain fluorescent green;excitation/emission maxima are 490/635 nm. Disk diffusion test, tubedilution method with neutralizing agent to quench residual activity(results shown in Table 1) and coated glass slides were the primarymethods of evaluating model compounds.

A variety of gram-positive and gram-negative bacteria were tested. A fewof the Gram+utilized included: Bacillus anthracis Sterne strain,Bacillus subtilis, Enterococcus faecalis, and Staphylococcus aureus.Gram-utilized included: Escherichia coli, Klebsiella pneumoniae,Pseudomonas aeguginosa, Salmonella typhimurium, Enterobacter cloacae,Proteus vulgaris, and Serratita marcescens.

TABLE 1 Biocide S. aureus E. Coli B. anthracis S. S. Pyridinium 10⁶ 10⁷10⁶ Phenol NG NG NG QUAT C₆ 10⁵ 10⁷ 10⁷ QUAT C₄ 10³ NG 10² Imideoxime10⁶ 10⁷ 10⁶ NG—no growth; starting cfu/mL: S. aureus, 5.46 × 10⁷; E.coli, 4.76 × 10⁷ and B. anthracis Sterne, 4.09 × 10⁷.

Quaternary ammonium biocides were subjected to minimum inhibitoryconcentration (MIC) studies for effectiveness comparisons (Table 2). TwoGram-positive bacteria (S. aureus and B. anthracis Sterne strain), wereemployed along with two Gram-negative bacteria (Escherichia coli andSalmonella typhimurium). In all cases, those biocides possessing theoctyl alkyl functionality were more effective antimicrobials than thecorresponding analogs possessing the hexyl group. The biocidespossessing the hexyl moiety appeared to be more effective againstGram-negative versus Gram-positive bacteria; while those possessing theoctyl moiety showed a lower MIC for Gram-positive bacteria versusGram-negative bacteria.

The comparison study of hydroxyl-terminated biocides (entries 9 and 10)with the corresponding methoxy terminated analogs (6 and 2)respectively, showed similar responses. The hydroxyl terminated octylderivative (9) was more effective than the corresponding hexyl analog(10) for three of the bacteria tested. While identical MIC results wereobtained for E. coli., with hydroxyl or methoxy terminated analogs. Thehydroxyl terminated hexyl (9) was more effective against Gram-positiveversus Gram-negative bacteria. The hydroxyl terminated octyl derivativedid not performed well with any of the bacteria tested.

When the alkyl functionality was held constant, the followingobservations were noted when the length of the hydrophilic oxyethyleneterminus was varied. In the case of the octyl functionality, in generalthe oxyethylene unit of 1 or 4 (5 and 8) was more effective as anantimicrobial than those possessing 2 or 3 units (6 and 7). Similarresults were observed for the hexyl analog, with lesser variances. Itwas noted that the additional oxyethylene unit assisted insolubilization, but no noticeable increase in antimicrobial activity wasobserved. It may be possible that aggregation into micelles could beaffecting antimicrobial activity by hindering the biocidal functionalgroups as seen in MIC for entries 2, 3, 6, and 7. Shorter linkagesresulted in an observed increased neutralization. The actual correlationof kill with oxyethylene chain length remains unknown and is the subjectof ongoing studies in our laboratory. No observable difference was notedbetween the two anions tested.

From results of this study, the antimicrobial activity can be listed asentry 5>8>7. These three biocides were effective against theGram-positive and Gram-negative bacteria tested. It was concluded thatthe octyl chain performed better than the corresponding hexylderivatives.

S. aureus B. anthracis E. coli S. typhimurium Entry Y m n X (Gram+)(Gram+) (Gram−) (Gram−) 1 CH₃ 5 1 Br 2.5 5 2.5 2.5 2 CH₃ 5 2 Br >5 >52.5 >5 3 CH₃ 5 3 Cl >5 2.5 2.5 >5 4 CH₃ 5 4 Cl 2.5 5 2.5 5 5 CH₃ 7 1 Cl0.18 <0.3125 0.625 2.5 6 CH₃ 7 2 Cl 0.31 1.25 2.5 5 7 CH₃ 7 3 Cl 0.50.625 2.5 2.5 8 CH₃ 7 4 Cl 0.8 0.3125 1.25 2.5 9 H 7 2 Cl 1.25 1.25 5 510 H 7 2 Cl >5 >5 5 >5

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It is therefore to beunderstood that the claimed invention may be practiced otherwise than asspecifically described. Any reference to claim elements in the singular,e.g., using the articles “a,” “an,” “the,” or “said” is not construed aslimiting the element to the singular.

1. A coating, comprising: an adhesive hydrophilic polymer; and anamphiphilic additive, wherein the amphiphilic additive has the formula:

wherein Y is CH₃ or H; and wherein m and n are independently selectedpositive integers.
 2. The coating of claim 1, wherein in is an integerfrom 1 to 17; and wherein n is an integer from 1 to
 8. 3. The coating ofclaim 1, wherein the adhesive hydrophilic polymer is selected from thegroup consisting of polyurethanes, polyurethane hydrogels, epoxies,polyesters, and polyacrylates.
 4. The coating of claim 1, wherein thecoating comprises more than one of the compounds; wherein the compoundshave more than one value for m, n, or both m and n.
 5. The coating ofclaim 1, wherein the coating further comprises a germinating agent. 6.The coating of claim 5, wherein the germinating agent is selected fromthe group consisting of L-alanine and L-methionine.
 7. The coating ofclaim 5, wherein the coating further comprises a nutrient.
 8. Thecoating of claim 7, wherein the nutrient is Luria broth.
 9. A compoundcomprising the formula:

wherein Y is CH₃ or H; and wherein m and n are independently selectedpositive integers.
 10. A mixture comprising more than one of thecompounds of claim 9; wherein the compounds have more than one value form, n, or both m and n.